Inadequate Outlet Grounding - umc_a001

[ZoomUptempo]

Had an electrician complete a 14-50 outlet in my garage utilizing a 50 amp GFCI breaker. After plugging the mobile connector I would get an error of “inadequate outlet grounding.” The electrician verified the all the connections, tested and everything checks out.
Past week, I troubleshooted still with no success.
- swapped with another 14-50 receptacle
- tried 50 amp breaker, non GFCI
- got a new mobile connector + 14-50 adapter (free from tesla, under warranty)

I looked at some YouTube videos trying to compare and see what is different. The one difference I see is that the copper wire was installed is stranded. Does a stranded copper wire matter? I noticed the electrician pig tailed a stranded copper wire to a solid one which is routed to the breaker box where it’s grounded. Is it possible the pig tail of stranded and solid copper be the problem? I checked the pig tail of it and it looks solid. Any insights and suggestions helps. Thank you in advance!

 

[Sophias_dad]

Stranded shouldn't matter, but its quite strange the electrician would go to the bother of adding a stranded pigtail.

Sounds like you really need to get the electrician back out. It shouldn't be your job to troubleshoot any more than you already have.

How sure are you that the ground wire is unbroken clear back to the panel, and is it properly connected in the panel?

 

[ZoomUptempo]

Stranded shouldn't matter, but its quite strange the electrician would go to the bother of adding a stranded pigtail.

Sounds like you really need to get the electrician back out. It shouldn't be your job to troubleshoot any more than you already have.

How sure are you that the ground wire is unbroken clear back to the panel, and is it properly connected in the panel?

I’m pretty sure the ground wire is clean and unbroken. I seen the electrician did the test with the meter and it’s good.
The electrician did come back and verified his work. Ensured the ground and all other wires are good attached securely and tightly. Electrician did the check with his device and, according to the electrician, everything checks out.

 

[Dave EV]

Do you have any issues charging off a regular 120V 15A outlet?

 

[ZoomUptempo]

Do you have any issues charging off a regular 120V 15A outlet?

No issues.

 

[Randy-12]

No issues.

Have you tried charging elsewhere with your mobile connector?
Is it your car?

Try charging at a friends place to see if it works.

 

[Sophias_dad]

I’m pretty sure the ground wire is clean and unbroken. I seen the electrician did the test with the meter and it’s good.
The electrician did come back and verified his work. Ensured the ground and all other wires are good attached securely and tightly. Electrician did the check with his device and, according to the electrician, everything checks out.

Take great care in inserting the adapter into the UMC body all the way, until the adapter is flush with the UMC body, and of course don't let the body hang from the adapter.

 

[Regaj]

Not all "grounds" are created equal. Part of that relates to things like the inherent soil resistivity at your home, moisture, temperature, building design - things you can't control. But part of it has to do with wiring/infrastructure topology, quality of materials used (wire, connectors, outlets, etc.). Many homes, even when wired to code, have poor grounds (defined as a ground with high resistance).

Very few electricians have the knowledge or tools to determine the actual quality of the ground at your home (and this is tacitly acknowledged by the NEC, the code source in most jurisdictions, wherein they would like you to get to 25 ohms or less resistance at your ground rod... but also give the option of driving two ground rods (bonded together)... and calling it good.).

All that's just the backdrop.

The best, most reliable place to get a "good ground" is in the main panel itself. As wiring runs move away from the panel, through outlets and other connections, often daisy-chained, and potentially through sub-panels... the opportunity for a missed or weak connection increases. If the hot or neutral leg is missed, that's obvious. The ground, less so. And simple volt-ohm meters won't necessarily catch a marginal ground.

I'd have the electrician come back out and ask him to assess/verify the specific wire run from your new 14-50 outlet in your garage... all the way back to the main panel. The ideal scenario would be where the main panel is also in the garage, close by. That's quick and easy to check. The further the panel is from the garage, the more chances for a sub-par connection at some point.

 

[estevens99]

ZoomUptempo,

I have a nearly identical issue with a new 14-50 outlet and mobile connector. "UMC_a001 Inadequate Grounding" error with two different mobile connectors but electrician tests everything as "good", including all of the wiring related to the ground and neutral wiring. I also tried a non-GFCI breaker with no luck.

Have you resolved your issue yet, and if so, what solved it?

 

[ZoomUptempo]

ZoomUptempo,

I have a nearly identical issue with a new 14-50 outlet and mobile connector. "UMC_a001 Inadequate Grounding" error with two different mobile connectors but electrician tests everything as "good", including all of the wiring related to the ground and neutral wiring. I also tried a non-GFCI breaker with no luck.

Have you resolved your issue yet, and if so, what solved it?

Yes I have but not with the 14-50 outlet. I had to purchase to Tesla wall charger. Since I already had the electrician do all the wiring, I youtubed on how to install the wall charger which was pretty easy.

 

[davewill]

Yes I have but not with the 14-50 outlet. I had to purchase to Tesla wall charger. Since I already had the electrician do all the wiring, I youtubed on how to install the wall charger which was pretty easy.

Fascinating. Since you were using the same wires, the ground should have been exactly the same and the car should have had the same error. Makes me wonder whether the electrician had the neutral and ground reversed on the 14-50 or some other similar dumb mistake. I suppose it could have even been a faulty outlet where the ground pin didn't make a good connection.

 

[estevens99]

I suppose it could have even been a faulty outlet where the ground pin didn't make a good connection.

Thank you for that theory!

Looking inside my Hubbell outlet, the ground's metal contacts are only on the left and right side of the "hole", so I experimented by applying sideways/diagonal force to my plug with it *slightly* unplugged and was able to get the "insufficient ground" error to go away. The moment I let go or push it in all the way, the error comes back.

Looking closer inside my Hubbell 14-50 outlet, the contacts inside the ground seem more flattened out than the other "holes", so your theory seems to be right in my case -- my outlet is defective/damaged/flawed and the ground pin from my plug is not making "enough" contact inside the outlet to avoid the "insufficient ground' error.

I am going to have my electrician replace the Hubbell outlet and if that does not work, I will follow ZoomUptempo's lead and swap for a Wall Connector.

Thanks!

 

[Rocky_H]

This is very familiar to another thread here on the forum, where someone had a Bryant brand 14-50 outlet, and the UMC would always report a ground error, but if they switched back to the cheap-o Leviton, it was grounded properly. Very strange.

Leviton 14-50 Works, Bryant 14-50 Doesn't - Same Wiring

Question for you all. Kinda at my wits end with this one, it just doesn't make any sense to me. I have had the issue of my Tesla charger dropping down to 16 amps from 32 amps after 30 minutes due to high outlet temperature. Turns out the usual culprit is the crappy Home Depot special Leviton...

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